Since the discovery of the cosmic microwave background radiation (CMB)
in 1965 [1]}, observations of the CMB have provided a
wealth of new information on the early and late time Universe. The
Planck satellitePlanck (http://www.esa.int/Planck) is a project of the European
Space Agency (ESA) with instruments provided by two scientific
consortia funded by ESA member states (in particular the lead
countries France and Italy), with contributions from NASA (USA),
and telescope reflectors provided by a collaboration between ESA
and a scientific consortium led and funded by Denmark
[2]}, [3]} is
the third space mission dedicated to measuring anisotropies in the
CMB, following COBE [4]} and WMAP [5]}, [6]}. The first cosmological results from the
Planck nominal mission temperature data were presented in
[7]} and results for the full missionThe nominal
mission comprises the first 15.5 months of data from Planck. The
full mission uses 29 months of data for the Planck High Frequency
Instrument (HFI) and 48 months for the Low Frequency Instrument
(LFI)., including polarization data, have been reported in
[8]} and [9]}. To extract cosmological information
from CMB data requires the construction of a likelihood. The
likelihoods used in the Planck analysis are described in abbreviated
form in [10]}, [11]}, [12]}This paper will refer
extensively to the Planck 2013, 2015 and 2018 cosmological
parameters papers [7]}, [8]}, [9]} , which will henceforth be referred to as PCP13,
PCP15 and PCP18. The corresponding likelihood papers will be
referred to as PPL13, PPL15 and PPL18..
